The present disclosure relates to a light emitting device.
There is known a light emitting device including a laser element and a phosphor member on a base which allows a laser beam to enter the phosphor member, thereby emitting light from the upper face of the phosphor member. See, for example, Japanese Patent Publication No. 2010-251686. This light emitting device includes a package which has a window above the base, and the light re-emitted from the upper face of the phosphor member is extracted from the window.
The light emitting device disclosed in the foregoing patent document has poor light extraction efficiency because a laser beam enters a lateral face of the phosphor member, and light is extracted from the upper face of the phosphor member. In other words, the use of light is reduced because light is absorbed or scattered inside the phosphor member during a duration from the time that a laser beam enters a lateral face of the phosphor member to the time that light exits the upper face of the phosphor member.
A conceivable construction for allowing a laser beam to enter the upper face of the phosphor member and extracting light from the same face includes, for example, an optical member such as a prism disposed between the laser element and the phosphor member in such a manner as to change the laser beam's traveling direction towards the upper face of the phosphor member using the optical member. In this case, however, there is a possibility of allowing a portion of the laser beam entering the optical member to travel directly towards the window as stray light; thus, there is room for improvement from the safety standpoint.